28765 has 8 divisors (see below), whose sum is σ = 37728. Its totient is φ = 20880.

The previous prime is 28759. The next prime is 28771. The reversal of 28765 is 56782.

It is an interprime number because it is at equal distance from previous prime (28759) and next prime (28771).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28765 - 2¹¹ = 26717 is a prime.

It is a Duffinian number.

28765 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207 + ... + 316.

It is an arithmetic number, because the mean of its divisors is an integer number (4716).

2²⁸⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

28765 is a deficient number, since it is larger than the sum of its proper divisors (8963).

28765 is a wasteful number, since it uses less digits than its factorization.

28765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539.

The product of its digits is 3360, while the sum is 28.

The square root of 28765 is about 169.6024763970. The cubic root of 28765 is about 30.6399552113.

The spelling of 28765 in words is "twenty-eight thousand, seven hundred sixty-five".